Districts Lifted by Tech Glitz

For decades, the area just south of San Francisco's City Hall was a grimy strip of aging midrise buildings pockmarked with payday-loan shops and panhandlers. But over the past two years, technology companies have gobbled up office space in the area, known as Mid-Market. Now, young software engineers fill the streets, cranes for new apartment towers rise on long-vacant lots, and among the many new retailers are a candy store that sells toffee for $22.95 a pound.